Method for making a cable splice joining a pair of flexible conducting cables

ABSTRACT

A cylindrical metallic sleeve has opposite end portions and a cylindrical body portion with a longitudinal passageway for receiving the end portions of a conducting cable in overlapping relation. A shaped annular portion is formed adjacent the sleeve end portions and includes an inner, outwardly flared cylindrical surface and an outer cylindrical surface that intersect in a rounded end portion. The outer cylindrical surface is planar and positioned substantially parallel to the sleeve cylindrical body portion so that the insulation surrounding the cables adjacent the sleeve end portions is not abraded upon flexing the spliced cable. The flared inner surface is removed from contact with the overlapping cable end portions in the sleeve to permit flexing of the cable end portions therein without abrading the cables. The sleeve body is crimped into frictional engagement with the overlapped cable end portions. The exposed portions of the spliced conductor cable are enclosed with insulating materials to provide a flexible, insulated cable splice that may be wound around a cable reel and/or guide sheaves.

CROSS-REFERENCE TO RELATED APPLICATION

This is a division of application, Ser. No. 562,228 filed Mar. 26, 1975,entitled "Flexible Cable Splice", now Pat. No. 3,980,806, which in turnis a continuation-in-part of patent application, Ser. No. 179,445 filedon Sept. 10, 1971, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method for making a cable splice joining thebroken end portions of a flexible electrical cable and more particularlya method for splicing together the broken end portions of a flexiblecable that includes a formed metallic sleeve arranged to frictionallyengage the joined cable end portions and permit optimum flexing of thecable without destroying the cable splice.

2. Description of the Prior Art

In underground mining substantially all of the equipment is electricallydriven and the power is supplied by means of conductor cables. Theconductor cables extend for substantially long distances and whenconnected to movable mining equipment are subjected to abrasion,moisture and frequent flexing, as for example, when the cable is woundon a cable reel and when the cable extends around pulleys mounted on themining equipment. Adverse conditions to which the cable is subjectedfrequently result in a parting of the conductors and it is necessary toeither splice or replace the cable before mining operations can resume.A splice, therefore, should be made with a minimum of tools at thelocation of the break in the cable and by one having ordinary skillswith the tools.

When the broken cable is spliced in the field such as in a minehaulageway, the cable must meet minimum conditions in that it bemoisture-resistant and retain flexibility to be wound on the cable reelwithout parting the splice. It is highly desirable to provide a splicethat will part when the cable is subjected to a tensile strength up tobut not in excess of the maximum safe tensile strength of the cable. Thecable can then be respliced at the previous splice in a shorter periodof time than is required to prepare a new splice. There are alsoregulations that limit the number of splices that can be made in thecable used in underground mining.

Conventional compression-type couplings for joining parted end portionsof an electrical cable are well known in the art. The ends of theconductors are positioned in a tubular coupling, and the tubularcoupling is crimped to secure the ends of the cable therein. The coupledcable is then provided with a moisture-resistant splice in whichshrink-type tubings are positioned over the coupling at the splice, andheat is applied thereto to shrink the tubings as an outer jacket on thesplice. Insulation may then be applied between the tubing and themetallic coupling.

The compression-type couplings frequently provide a greater tensilestrength at the splice than the tensile strength of the conductor.Consequently, cable failure results at locations in the cable remotefrom the splice. Further, the compression-type couplings utilized incable splices have a length which limits the travel of the splices overa pulley and the winding of the cable on a cable reel. This results inabrasion of the metallic conductor by the sharp end portions of the tubewhich restrain the spliced conductor from flexing. In addition, manytubular compression-type couplings have sharp peripheral edges thatabrade or sever the insulation surrounding the cable splice uponflexing.

An example of a compression-type coupling is disclosed in U.S. Pat. No.2,276,571 having a splice for joining together ends of electrical wireswhere the ends are inserted in a metal tube or sleeve that has flaredend portions. After inserting the wire ends in the metal sleeve, thewires are twisted in opposite directions to effect intermingling of thestrands of one wire with those of the other wire. The middle portion ofthe metal sleeve is then flattened by means of pliers whereby the sleeveand wires therein are compressed together to form a splice. Compressingthe sleeve in this manner does not limit the degree of flatteningimparted to the malleable tube so that the tensile strength in thesplice is less than the tensile strength of the cable being spliced.

Intermingling of the strands of one wire with those of the other canallow stretching of the splice when the cable splice is under tension.Interweaving of the cable strands in this manner exerts a pull on onlypart of the copper strands initially and creates a stretching during usewhich ultimately destroys the insulating and water-tight seal on thesplice. Further, the elongated tube when flattened provides aninflexible splice that could not be wound about a pulley or a cable reelwithout the sharp end portions of the tube cutting into and severing theinsulation and the strands of wire at the entry and exit of the wire atthe ends of the tube. Tests have revealed that substantially all of thecable splice failures are attributed to the cutting off of the conductorstrands by the sharp peripheral edges of the metallic sleeve on flexingof the cable.

Cable splices and connectors that frictionally engage the conductors andinclude flared end portions are illustrated in U.S. Pat. Nos. 3,120,023and 3,612,748. The former discloses an end cap in which a plurality ofcable end portions are positioned in a metallic cable member having asingle flared end portion. The latter is directed to an explosiveconnector that positions a plurality of cable end portions within acup-shaped connector that has an inner deformable shell and an outerrigid shell with an explosive positioned therebetween. The explosive isdetonated to distort the inner shell to engage the cable end portions.However, connectors of this type have sharp edge portions that are urgedinto contact with the cable upon flexing thereby abrading the cableultimately, resulting in cable failure. Furthermore, the elongatedconfiguration of the connectors in relationship to the diametersubstantially reduces the flexibility of the spliced cable causingabrasion of the cable by the inner edge of the connector as the cablepasses around a pulley or cable reel.

U.S. Pat. Nos. 2,314,884 and 2,467,913 disclose splices for electricalconductors in which the parted end portions of the cables are eitherpositioned in abutting relationship or in overlapping relationship witha metallic tube. A plurality of crimped indentations are formed on theperiphery of the metal tube to thereby secure the cable end portionswithin the metallic tube. U.S. Pat. Nos. 3,258,522 and 3,387,364disclose encapsulating a spliced electrical conductor with a rubber-likematerial such as vulcanized silicone rubber to insulate the conductorsplice and protect the splice from the adverse effects of moisture,abrasion and the like.

There is need for a method of joining the broken end portions of aconducting cable by a metallic sleeve that preserves the cable spliceadjacent the end portions of the sleeve by reducing abrasion by thesleeve as the spliced cable passes around a pulley or is wound on acable reel and has a tensile strength up to but not in excess of themaximum safe tensile strength of the cable being spliced.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided a method formaking a cable splice for joining a pair of flexible conducting cablesthat includes shaping the end portions of a metallic sleeve having acylindrical body by cutting the sleeve body along a diagonal fromadjacent the end portions. The inner cylindrical surface of the bodyadjacent the cut end portions is flared radially outwardly to formrounded end portions with the outer surface of the cylindrical body.Thus, the diagonal cut portion of the sleeve body is urged to a positionparallel to the outer surface of the cylindrical body to form adjacentthe sleeve end portions annular portions having flared inner surfacesand rounded end portions. The ends of the conducting cables having theinsulation stripped therefrom exposing the conductors are inserted intoopposite ends of the sleeve with the ends of the cables in overlappingrelation. The sleeve is crimped to frictionally engage the ends of thecables in overlapping relation. Thereafter, the exposed ends of thecables and the sleeve are sealed to provide an electrically insulatedand moisture and abrasion resistant cable splice.

The metallic sleeve comprises a copper sleeve having a longitudinalpassageway therethrough with a diameter sufficient to receive a pair ofoverlapping cable end portions. Preferably, the copper sleeve has aninner cross sectional area of between about 0.040 and 0.050 square inchgreater than the sum of the cross sectional areas of the cable endportions positioned therein for splicing. The shaped annular portions ofthe sleeve are formed by a first portion on the outer cylindricalsurface of the sleeve extending diagonally from a point adjacent thesleeve end portion and terminating in a rounded portion at the sleeveend portion. With this arrangement, the end portion has a thickness lessthan the thickness of the body portion. A second portion of the shapedannular portion includes the inner cylindrical surface of the bodyportion flared outwardly adjacent the sleeve end portion such that thefirst portion is urged into alignment with the outer surface of thesleeve body portion.

In a specific embodiment of the present invention, the outer cylindricalsurface of the shaped annular portion is positioned substantiallyparallel to the cylindrical body portion such that the outer cylindricalsurface of the shaped annular portion and the cylindrical body portionform a planar end portion of the sleeve. A further embodiment of thepresent invention includes the shaped annular portion having the roundedend portion of a preselected radius of curvature and the planar surfaceof a preselected length positioned substantially parallel to thecylindrical body portion. The planar surface of the annular portion maybe positioned beyond or within the outer cylindrical surface of the bodyportion, but in either position the planar surface is positionedsubstantially parallel to the sleeve body portion. With thisarrangement, the sleeve end portions are removed from contact with thecable upon flexing of the cable thus preserving the cable splice byreducing the abrasion of the cable by the end portions of the sleeve.

With the cable end portions joined together within the metallic sleeve,a band of crimping indentations are positioned substantiallyintermediate the shaped annular treated portions of the sleeve. Bydeforming the sleeve body portion by forming the crimping indentationstherein, the body portion frictionally engages the overlapped cable endportions in the longitudinal passageway of the sleeve with a frictionalforce that is less than the tensile strength of the cable being spliced.Preferably, the tensile strength of the spliced cable is about 85% ofthe maximum safe tensile strength of the cable being spliced. Thus, thespliced cable will part at the splice when subjected to tensile forcesthat approach the same tensile strength of the cable so that the cablecan be more readily respliced at the previous splice rather thanpreparing new ends of the cable for splicing.

To protect the spliced cable from the adverse conditions to which it issubjected, an insulated watertight splice is formed and includes a firstwrapping of a binding tape over the overlapping spliced cable endportions. A layer of an insulating putty is positioned around the cablesplice. Then a plurality of layers of insulating tape are applied overthe insulating putty and the first wrapping such that the cable spliceis electrically insulated and sealed against the deleterious effects offire, moisture and abrasion.

Accordingly, the principal object of the present invention is to providea method for joining broken cable end portions of an electrical cable bya metallic sleeve having a cylindrical body portion with shaped annularportions positioned adjacent the sleeve end portions that serve toreduce abrasion to the conductor and the protective insulation surroundthe conductor as the cable splice is flexed.

A further object of the present invention is to provide an improvedmethod for joining the parted end portions of an electrical cable with adeformable metallic sleeve having shaped annular portions that arespaced from contact with the cable end portions and have an inner curvedsurface that provides end clearance between the end portion of thesleeve and the cables therebeneath so that upon bending the cable theclearance between the cable and sleeve reduces the abrasion to the cableby the end portions of the sleeve.

Another object of the present invention is to provide a method forjoining a pair of conducting cables that includes a metallic sleevehaving a preselected length and diameter that permits optimum flexing ofthe spliced cable as it passes over cable pulleys and is wound on acable reel without subjecting the cable to abrasion by the sleeve endportions.

A further object of the present invention is to provide an improvedmethod for splicing the parted end portions of a flexible electricalcable so that the splice has a tensile strength up to but not in excessof the maximum safe tensile strength of the cable being spliced.

An additional object of the present invention is to provide a method forsplicing the parted end portions of a flexible electrical cable that maybe easily and efficiently installed in the field to provide a splicedcable having a preselected tensile strength and electrically insulatedand protected from the effects of fire, moisture and abrasion.

These and other objects of the present invention will be more completelydescribed in the following specification, the accompanying drawings andthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an enlarged sectional view in side elevation of a cylindricalmetallic sleeve for joining a pair of conducting cables to form aflexible cable splice, illustrating the sharp end portions of the sleeveto be shaped in accordance with the present invention.

FIG. 2 is an enlarged sectional view in side elevation of the metallicsleeve, illustrating the first step of shaping the sleeve end portions.

FIG. 3 is an enlarged sectional view in side elevation of the metallicsleeve, illustrating the second step of shaping the sleeve end portionsto provide annular portions having rounded end portions that reduceabrasion to the cable.

FIG. 4 is an enlarged sectional view in side elevation of the metallicsleeve, illustrating the metallic sleeve with the shaped annularportions extending beyond and positioned substantially parallel to theouter surface of the sleeve body portion.

FIG. 5 is a view similar to FIG. 4, illustrating the metallic sleevewith the annular portions positioned within and substantially parallelto the outer surface of the sleeve body portion.

FIG. 6 is a schematic representation of a pair of conducting cable endportions, each comprising bundles of individual copper strands with aportion of the jacket insulation removed therefrom, illustrating thecable end portions in overlapping relationship with one of the cable endportions having the metallic sleeve positioned thereon.

FIG. 7 is a schematic representation similar to FIG. 6, illustrating themetallic sleeve joining the cable end portions in overlappingrelationship.

FIG. 8 is a schematic representation similar to FIG. 7, illustrating themetallic sleeve crimped into pressing contact with the overlapping cableend portions to join the cable end portions.

FIG. 9 is a view in side elevation, partially in section, of the cableend portions spliced together by the crimped metallic sleeve with themetallic sleeve and the exposed end portions of the cables sealed by anelectrically insulated, moisture and flame resistant jacketing tape.

FIG. 10 is a view in side elevation of a splicing tool for forming thecrimping indentations in the metallic sleeve.

FIG. 11 is a schematic view of an electrical conductor having cable endportions joined together by the metallic sleeve of the presentinvention, illustrating flexing of the spliced cable by the cable spliceas the conductor is passed around a pulley.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings and particularly to FIGS. 1-5, there isillustrated a deformable metallic sleeve generally designated by thenumeral 10 for joining a pair of overlapping conducting cable endportions of a metallic conductor in accordance with the presentinvention. The metallic sleeve 10 comprises a continuous cylindricalcopper body portion 12 of a preselected thickness forming a longitudinalpassageway 14 therethrough with a diameter sufficient to receive a pairof overlapping cable end portions. Preferably, the length of the bodyportion 12 is about seven-eighths inch so as to insure a flexible cablesplice as will be explained hereinafter in greater detail. According tothe present invention, as illustrated in FIG. 3, the cylindrical bodyportion 12 is provided with shaped annular portions 16 and 18 positionedadjacent opposite end portions 20 and 22 of the sleeve 10. The annularportions 16 and 18 each includes an outwardly flared inner cylindricalsurface 19 and an outer cylindrical surface 21 that form a rounded endportion 23 having a preselected radius of curvature. The outer surface21 is positioned substantially parallel to outer cylindrical surface 24of the sleeve 10, and as illustrated in FIG. 3, surface 21 is alignedwith surface 24 to form planar end portions of the sleeve 10.

As illustrated in FIG. 1, prior to shaping the copper body portion 12the sleeve 10 is fabricated from stock material having a uniform insideand outside diameter that defines opposite end portions 20 and 22. Withthis arrangement, the metallic sleeve 10 has a planar cylindrical outersurface 24 and an inner cylindrical surface 26 extending from endportion 20 to end portion 22. The end portions 20 and 22 terminate insharp corners 25 that are shaped in accordance with the presentinvention to preserve the conductor and reduce abrasion to theinsulation surrounding the cable splice.

Referring to FIG. 2, the corners 25 of sleeve end portions 20 and 22,illustrated in FIG. 1, are shaped by initially cutting or grinding theend portions to form a first portion of length L on the outer surface 24extending diagonally from a point adjacent the sleeve end portion to apoint between the inner surface 26 and the outer surface 24 at thesleeve end portion. The remaining portion between the outer and innersurfaces 24 and 26 is rounded to form a sleeve end portion having apreselected radius of curvature R. Preferably, the radius of curvatureis between about 0.020 and 0.025 inch. The length L of the diagonal cutportion illustrated in FIG. 3 is determined by the thickness of the bodyportion 12 and preferably is cut on a 15° diagonal.

The sleeve 10 is further shaped, as illustrated in FIG. 3, by flaringthe inner cylindrical surface 26 adjacent the end portions 20 and 22 ofthe body portion 12 radially outwardly at a preselected angle with asuitable flaring tool to form inner cylindrical surfaces 19 thatintersect with the outer cylindrical surfaces 21 to form the rounded endportions 23. The inner cylindrical surfaces of the thus formed annularportions 16 and 18 are flared outwardly to the extend that the diagonalcut portion L illustrated in FIG. 2 is urged into alignment with theouter cylindrical surface 24 of the body portion 12. In this manner, thesharp peripheral edges 25 of the sleeve 10 illustrated in FIG. 1 areremoved. The outer diameter of the opposite end portions 20 and 22 andouter surfaces 21 of the annular portions 16 and 18 are positionedsubstantially parallel to the sleeve outer surface 24.

In accordance with a specific embodiment of the present invention, aflexible cable splice comprising the metallic sleeve 10 with the bodyportion 12 of a thickness of about 0.090 inch, the annular portions 16and 18 are shaped as illustrated in FIG. 3. With this arrangement, theouter surfaces 21 of the annular portions 16 and 18 are aligned with theouter surface 24 of the sleeve 10 to form a sleeve having planar endportions with flared inner surfaces 19 terminating in the rounded endportions 23.

Preferably, for sleeves having a body portion of a thickness less than0.090 inch, annular portions 28 and 30 having rounded end portions 32are shaped as illustrated in FIG. 4. The annular portions 28 and 30include an outer cylindrical surface 34 of length L positioned parallelto the cylindrical surface 24. The annular portions 28 and 30 are formedby inserting a suitable flaring tool within the sleeve end portions 20and 22 and exerting a radial force thereon until the diagonal cutportions are urged to a position parallel to the outer cylindricalsurface 24 of the body portion 12. With this arrangement, the outersurfaces 34 of the annular portions 28 and 30 extend beyond the outercylindrical surface 24.

Referring to FIG. 5, in accordance with the present invention, there isillustrated a further embodiment of the sleeve 10 having shaped annularend portions 31 and 33 with the outer cylindrical surfaces 34. Theannular end portions 31 and 33 are formed as above described and includethe outwardly flared inner cylindrical surfaces 19 that intersect withthe planar outer cylindrical surfaces 34 to form the rounded endportions 32. However, in flaring the sleeve end portions 20 and 22, thediagonal portion of length L is urged to a position substantiallyparallel with the sleeve outer surface 24 but the planar surfaces 34thus formed are positioned within the outer surface 24. This arrangementis preferred for a sleeve having a body portion of a thickness greaterthan 0.090 inch. Thus, for a sleeve having a body portion of a giventhickness the flared annular end portions may be shaped in a preselectedmanner to insure a flexible cable splice. The sharp peripheral edges 25illustrated in FIG. 1 are eliminated by shaping the sleeve end portionsto provide flared annular portions of a desired configuration selectedfrom the configurations illustrated in FIGS. 3-5. In this manner, themetallic sleeve 10 is operable to preserve the life of the cable spliceby reducing the abrasion to the cable splice insulation and insuringoptimum flexibility of the spliced cable.

With a metallic sleeve 10 having the shaped annular portions 28 and 30,a cable splice, as illustrated in FIG. 11, is provided with flared innercylindrical surfaces 19 that are removed from contact with theoverlapping cable end portiond 37 and 39 as the cable passes over apulley 40. Furthermore, the outer planar surfaces 34 and the rounded endportions 32 of the annular portions 28 and 30 reduce abrasion to theinsulation surrounding the sleeve upon flexing of the cable. Inaddition, the provision of the annular portions 28 and 30 with theflared inner surfaces 19 facilitates the positioning of the overlappingcable end portions in the sleeve 10. Thus, the flared inner surfaces 19with the rounded end portions 32 eliminate the sharp peripheral edges ofthe sleeve and preserve the conductor by providing clearance at thesleeve end portions between the sleeve flares and the conductor whenpassing over a sheave. The shaped annular portion 28 and 30 formed inthe above described manner, also provide for additional strength in themetallic sleeve 10 which helps to maintain the cylindrical shape of thesleeve end portions upon crimping.

Referring to FIG. 6, there is illustrated a pair of cable end portions43 and 44 which have metallic conductors 46 and 48 enclosed or coveredwith insulation 50 and 52. The layer of insulation 50 and 52 isconventionally applied to the metallic conductor as a continuous layerand may be formed from various materials such as polyvinylchloride,neoprene or other rubber-like polymers.

In forming a cable splice according to the present invention, the endsof the cables 43 and 44 are trimmed to remove a section of theinsulation to expose the conductors 46 and 48 and provide annular endportions 54 and 56 stripped of the insulation 50 and 52. One of thetrimmed cable end portions such as end portion 54 is inserted into themetallic sleeve 10 as illustrated in FIG. 6. The inner diameter of thesleeve 10 is selected so that there is preferably an inner crosssectional area of between about 0.040 and 0.050 square inch greater thanthe sum of the cross sectional areas of the cable end portions 54 and 56positioned therein. A clearance area of this size is sufficiently largeto easily insert the pair of conductors and, as described hereinafter,permit crimping or compression of the flared sleeve 10 to properlyengage the cable end portions. Also, the inner diameter of the sleeve 10is preferably selected for different sizes of cable to provide thisclearance area of 0.040 and 0.050 square inch to get a common clearancearea in the sleeves used for different sized cables. As stated above,the sleeve 10 preferably has a length of seven-eighths inch which issufficient to receive the cable end portions 54 and 56 in overlappingrelationship and permit flexing of the spliced conductors within thesleeve as the cable is wound upon a cable reel and/or guide sheaves. Itis the provision of the shaped annular portions 34 and 36 that insures aflexible cable splice with reduced abrasion to the insulationsurrounding the sleeve.

To permit ease of entry of the cable end portion 54 into thelongitudinal passageway 14 of sleeve 10, the end portion 54 ispreferably flat. The sleeve 10 is then advanced along the exposed cableend portion 54 until the sleeve end portion 20 reaches a positionadjacent the insulation 50 on the conductor 46. Thereafter, the sleeve10 is advanced on the cable end portion 54 toward the cable end portion56, making certain that the cable end portion 54 remains within thepassageway 14, and the cable end portion 56 is guided into the sleeveend portion 22. By twisting the sleeve and pushing both cable endportions 54 and 56 through the passageway 14, the sleeve 10 is advancedto the position illustrated in FIG. 7.

As illustrated in FIG. 7, the cable end portions 54 and 56 extend inoverlapping relationship through sleeve end portions 20 and 22,respectively. The cable end portions 54 and 56 are further pushedthrough the sleeve 10 until the end portions are positioned insubstantially abutting relationship with the insulation 50 and 52 of therespective conductors 46 and 48, as illustrated in FIG. 8. Then the freeend portions 54 and 56 extending through the sleeve 10 are pressedaround the mating cable to surround the mating cable in approximately a180° relationship. With this arrangement, the metallic sleeve 10 joiningthe cable end portions is ready for crimping and sealing with tape andinsulation.

A plurality of crimping indentations 58 illustrated in FIG. 8 are formedin the sleeve 10 by a cable splicing tool generally designated by thenumeral 60 in FIG. 10. The cable splicing tool forms a band of thecrimping indentations 58 around the periphery of the center portion ofthe sleeve 10 in the same transverse plane through the sleeve 10.

The cable splicing tool 60 illustrated in FIG. 10 includes a pair ofopposed guide housings 62 and 64 adapted to be fitted together inabutting relationship. Each of the opposed die housings 62 and 64includes a semicircular die 66 and 68 respectively. Dies 66 and 68extend longitudinally of their respective die housing. With thisarrangement, the opposed die housings 62 and 64 fit together in abuttingrelationship to form a channel-shaped printing die extendinglongitudinally through the abutting die housing.

Each semicircular die 66 and 68 includes a pendant arrangementprojecting radially inwardly thereof. As illustrated in FIG. 10, thependant arrangement comprises ball bearings 70. Ball bearings 70 areseated and maintained in position with the semicircular dies 66 and 68and respective seats 72 formed therein. Each of the seats 72 comprises abore formed, as by drilling, in die housings 62 and 64. Each of theseats 72 is located along a circle of a vertical section through thechannel-shaped die formed by the semicircular dies 66 and 68. Each ofthe seats 72 is drilled to a preselected depth within a die housing. Adesired portion of the ball bearing 70 extends through the wall of asemicircular die for forming the pendant arrangement that projectsradially inwardly thereof. The ball bearings 70 are held in place in thedie housing seats 72 by the center punch indentations made in thesemicircular dies 66 and 68 at two points adjacent each of the seats 72.

To form the cable splice according to the present invention, the cableend portions 54 and 56 joined together by the metallic sleeve 10 areinserted in semicircular die 68 of die housing 64. Thereafter, thehousing 62 is placed atop the cables within the die as illustrated inFIG. 10. With this arrangement, the ball bearing pendant arrangements 70are located along a circle taking the vertical section above described.To insure proper alignment of the semicircular die cavities, each of thedie housing 62 and 64 is provided with a pair of bores 74 and 76. Thebore pairs 74 and 76 are vertically aligned to receive the dowel pins 78that prevent sliding or slipping of the die housings 62 and 64. Withthis arrangement, the ball bearings 70 are maintained in properposition. The dowel pins 78 are vertically supported by a base plate 80.

After opposed die housings 62 and 64 have been properly aligned with thepair of cable end portions 54 and 56 retained in the metallic sleeve 10,a crimped splice may be formed. To complete the crimped splice, a forceis exerted on the closed die housing 62 and 64 to urge the housingstoward abutting relationship and to compress the ball bearings 70 intothe sleeve 10 having the overlapping end portions 54 and 56 positionedtherein. In this manner, a crimped cable splice is formed having a bandof crimping indentations 58 formed around the periphery of the sleeve 10in the same transverse plane therethrough. The striking force requiredto crimp the sleeve cables 54 and 56 is applied to a striking surface 82that projects upwardly from the die housing 62. By striking the surface82 with a suitable tool, such as a hammer, a force is exerted on theopposed die housings 62 and 64 urging them toward each other.

In accordance with the practice of the present invention, the crimpedsplice, as illustrated in FIG. 8, is formed by exerting a few strikingforces upon the surface 82 to make initial crimping indentations 58 inthe periphery of the sleeve 10 and joining in overlapping relationshipthe cable end portions 54 and 56. Thereafter, the cable splice isrotated within the die until the initial crimping indentations arealigned in the same transverse plane of the next adjacent ball bearings70. Striking surface 82 is then again struck with a hammer. The cable isonce again rotated and a striking force applied to surface 82 until diehousing 62 "bottoms out" on die housing 64. With this arrangement, thedie housings are positioned in abutting relationship.

By providing a die which "bottoms out" the degree of crimping and thestrength of the cable splice is exactly controlled. It is, therefore,not possible to overcrimp a cable splice. Furthermore, by providing thesleeve 10 with the above described shaped annular portions, thecylindrical shape of the end portions of the sleeve is maintained uponcrimping.

As illustrated in FIGS. 9 and 11, the crimping indentations 58 formed inthe sleeve 10 have a spherical configuration with a radius of curvatureequal to that of the ball bearings 70. The spherical crimpingindentations 58 substantially and uniformly reduce the stressconcentrations applied to the conductor at the crimp location. Ascompared to square crimping indentations having sharp corners with highstress concentrations, the spherical indentations 58 eliminate sharpcrimp corners. Thus, elimination of sharp crimp corners and theaccompanying high stress concentrations substantially reduces cablefailure associated therewith, particularly upon flexing of the cable atthe splice.

The cable splice formed by the present invention has a maximum safetension up to but not in excess of the maximum safe tensile strength ofthe cable being spliced. It is preferred that the cable splice have atensile strength of about 85% of the maximum safe tensile strength ofthe cable being spliced. Further in accordance with the presentinvention, the above described cable splice can readily be accomplishedin the field. The only tools required for forming the splice are thecable splicing tool 60 and a hammer of the like. Thus, the broken cablemay be rapidly and efficiently spliced and returned to service.

Further, with this type of splice the cable will part at the splice whensubjected to tensile forces that approach the safe tensile strength ofthe cable so that the cable can be more readily respliced at theprevious splice rather than preparing other parted ends of the cable forsplicing.

After the cable end portions 54 and 56 are frictionally engaged bycrimping the sleeve 10 in the above described manner, the exposed endsof the cable are wrapped with three to four wraps of a strongcompressive tape 84, such as a glass cloth tape or plastic electrician'stape, as illustrated in FIG. 9. An insulating putty 86 is spread overthe entire spliced area between the insulating materials 50 and 52 onthe cables 54 and 56. Sufficient insulating putty 86 is applied to thesleeve and spliced area to completely fill the uninsulated area to adiameter equal to or slightly larger than the outside diameter of theinsulation 50 and 52. A suitable insulating filler putty is sold by theOkonite Company, Ramsey, N.J. under the trade name Okonite Filler Putty,No. 602758010. A layer of insulating material 88 may be placed over theputtied spliced area. Preferably, the insulating material 88 comprises afabric-like tape.

The surface of insulations 50 and 52 on the conductors 46 and 48 isroughened for a length of several inches of the cable splice. A suitableliquid cement is applied to the entire roughened section and to thefiberglass tape 88. The splicing cement preferably comprises a neoprenesplicing cement. The entire cement-coated area is then covered with athin layer of an insulating putty 90 of the same material as theinsulating putty 86. A final outer layer of insulating tape 92 isapplied lengthwise of the splice for additional sealing and insulatingpurposes. A suitable insulating tape 92 is available under the tradename "Okonite No. 35 Red Jacket" manufactured by the Okonite Company, inRamsey, N.J.

An end cap 94 for the insulation and sealing materials is provided andmay comprise a several layered wrap of an insulating tape such as theabove mentioned insulating tape 92. Thus, it will be apparent from theabove described splice that a broken cable can be quickly andefficiently spliced in the field to provide a flexible cable splice thatis electrically insulated and has moisture and abrasion resistantproperties that permit full operation of the spliced conductor underadverse conditions and repeated flexing without destroying of the cablesplice.

According to the provisions of the patent statutes, I have explained theprinciple, preferred construction and mode of operation of my inventionand have illustrated and described what I now consider to represent itsbest embodiments. However, it should be understood that, within thescope of the appended claims, the invention may be practiced otherwisethan as specifically illustrated and described.

I claim:
 1. Method for making a cable splice joining a pair of flexibleconducting cables comprising,shaping the end portions of a metallicsleeve having a cylindrical body by cutting said sleeve body along adiagonal from adjacent said end portions, flaring the inner cylindricalsurface of said body adjacent said cut end portions radially outwardlyto form rounded end portions with the outer surface of said cylindricalbody, urging said diagonal cut portion of said sleeve body to a positionparallel to the outer surface of said cylindrical body to form adjacentsaid sleeve end portions annular portions having flared inner surfacesand rounded end portions, inserting the ends of the conducting cableshaving the insulation stripped therefrom and the conductors exposed intoopposite ends of said sleeve with the ends of the cables in overlappingrelation, crimping said sleeve to frictionally engage the ends of thecables in overlapping relation, and sealing the exposed ends of thecables and said sleeve to provide an electrically insulated and moistureand abrasion resistant cable splice.
 2. The method for making a cablesplice joining a pair of flexible conducting cables as set forth inclaim 1 which includes,urging said diagonal cut portion of said sleevebody to a position in alignment with the outer surface of saidcylindrical body to form a sleeve having planar end portions with flaredinner surfaces terminating in rounded end portions.
 3. The method formaking a cable splice joining a pair of flexible conducting cables asset forth in claim 1 which includes,exerting a radial force upon saiddiagonal cut portion of said sleeve body to urge said diagonal cutportion to a position parallel to and extending beyond the outer surfaceof said cylindrical body and thereby form shaped annular portionsadjacent said sleeve end portions.
 4. The method for making a cablesplice joining a pair of flexible conducting cables as set forth inclaim 1 which includes,exerting a radial force upon said diagonal cutportion of said sleeve body to urge said diagonal cut portion to aposition parallel to and extending within the outer surface of saidcylindrical body and thereby form shaped annular portions adjacent saidsleeve end portions.
 5. The method for making a cable splice joining apair of flexible conducting cables as set forth in claim 1 whichincludes,shaping said sleeve end portions by cutting said end portionsto form a cut portion of a preselected length extending diagonally froma point adjacent said sleeve end portions to a position between theinner and outer surface of said cylindrical body at said sleeve endportions, and rounding said sleeve end portions between the inner andouter surface of said cylindrical body to form sleeve end portionshaving a preselected radius of curvature.
 6. The method for making acable splice joining a pair of flexible conducting cables as set forthin claim 1 which includes,cutting said cylindrical body adjacent saidsleeve end portions at an angle of 15° extending diagonally from a pointadjacent said sleeve end portions to a position between the inner andouter surfaces of said sleeve end portions.
 7. The method for making acable splice joining a pair of flexible conducting cables as set forthin claim 1 which includes,flaring the inner cylindrical surface of saidbody portion adjacent said cut portions radially outwardly at apreselected angle to form an inner cylindrical surface intersecting theouter surface of said cylindrical body to form a sleeve having roundedend portions.
 8. The method for making a cable splice for joining a pairof flexible conducting cables as set forth in claim 1 whichincludes,wrapping the exposed ends of said conductors between saidsleeve and the insulation remaining on said conductors with acompressive tape, applying an insulating putty to said sleeve and thewrapped ends of said conductors to a diameter slightly larger than thediameter of the insulation on said conductors, wrapping a first layer ofinsulating tape around the insulation on said conductors and said puttysurrounding said sleeve and wrapped ends of said conductors, roughing asection of the surface of the insulation on said conductors adjacentsaid sleeve, applying a liquid cement to the roughened section and tosaid insulating tape, wrapping the cemented area with a second layer ofinsulating tape, and sealing the end portions of said layer ofinsulating tape with a third layer of insulating tape to provide anelectrically insulated and moisture and abrasion resistant flexiblecable splice.